In health and epidemiological research, the Healthy Lifestyle (HLS) is often invoked as an explanation for inconsistent effects. Modifiable components of the HLS are advocated as a panacea for the most common threats to public health. Biases resulting from the HLS are theorized to result from covariance among its components. This covariance has not yet been formally modeled. Furthermore, no mechanism has been proposed to explain this covariance among these factors. Using three large nationally representative samples, I evaluated the HLS as a latent variable. Using structural equation modeling (SEM) I evaluated the degree to which the shared variance of HLS components is accounted for by personality traits, and tested the HLS as a mediator of the personality health relationship. Across all three samples, the HLS fits well as a latent variable, is partially accounted for by personality traits, and mediates the effects of personality traits on health. In all cases personality traits have direct effects on health independent of the HLS. These results suggest that the utility of personality traits as predictors of health exceeds that provided by commonly used lifestyle predictors.